Rigid plastic door with slatted vane construction

ABSTRACT

Extruded plastic doors having two side stiles and a top and bottom rail forming a generally rectangular configuration and having horizontal vanes covering the interior of the door. The stiles have mating indentations along their interior edge for receiving the vanes and holding the vanes in a permanently fixed position relative to the stiles and rails when the stiles and rails are assembled into a rectangular configuration. The stiles, rails and vanes are formed by an extrusion process so as to have a substantially hollow interior with reinforcing cross-members.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not applicable.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] This invention relates to doors made from extruded plastic. Morespecifically, it relates to bi-fold or half doors made from rigidplastic, such as polyvinyl chloride (PVC). The side stiles, horizontalrails, and slatted vanes that make up the door are individual piecesthat are generally hollow, except for reinforcing interiorcross-members. The individual pieces are formed by extruding plasticthrough a die. The invention contemplates that the door be assembled ina manner similar to that used for a conventional wooden bi-fold door.

[0005] 2. Description of the Related Art

[0006] Traditionally, bi-fold or half doors have been made of wood, butthe expense of wood has caused the industry to search for other suitablematerials. Recently, manufacturers have turned to fabricating such doorsfrom synthetic resins by injection molding, as described in U.S. Pat.No. 3,985,175. However, the injection molding process is limited in itsapplication. Typically, the injection molding process involves makingtwo rectangular hollow pans and joining the pans together by the edgesto form a hollow door. U.S. Pat. No. 3,985,175 describes a particulartype of construction wherein a front face is made of injection moldedplastic and has reinforcing members on the back side but no back face.Such a construction, while serving to maintain rigidity, provides a doorhaving only one good side. Such a door is unsuited for generalapplications in the home or office.

[0007] One of the main problems with full length doors made frominjection molded plastic is their lack of rigidity. Therefore, there isa need in the industry for a plastic door that has sufficient rigidityand is aesthetically pleasing from both sides.

SUMMARY OF THE INVENTION

[0008] Full length bi-fold and half doors may be constructed from rigidplastic, such as PVC, that is extruded to form the various pieces usedto construct the door. Rigid plastic has the advantage of being lighterin weight than wood because the interior of the rails, stiles, and vanesare basically hollow except for the reinforcing cross-members that areformed during the extruding process. This type of construction offersseveral advantages over wood. A rigid plastic door is much more fireresistant than wood, and it does not warp from humidity. Additionally,the finished product manufactured from plastic does not require paintingand is a solid color throughout so scratches from ordinary use are notreadily visible. Finally, rigid plastic is easier to clean, can beproduced with a glossy finish, and is generally more durable than wood.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a schematic representation of a bi-fold door inaccordance with the present invention.

[0010] FIG.2 is a schematic representation of a half door in accordancewith the present invention.

[0011] FIG.3 is a cross-section view of a rail used for the top, middleand bottom horizontal support members.

[0012]FIG. 4 is a cross-section of the side support members or stiles.

[0013]FIG. 5 is a cross-section of a slatted vane that fits between theside stiles.

DETAILED DESCRIPTION OF INVENTION

[0014] The invention is directed to a full length bi-fold and half doorconstructed from synthetic resinous, rigid plastic that is extruded toform the various pieces used to make the door. Rigid plastic has theadvantage of being lighter in weight than wood because the interior ofthe rails, stiles, and vanes are basically hollow except for thereinforcing cross-members that are formed during the extruding process.This type of construction offers several advantages over wood. A rigidplastic door is much more fire resistant than wood, and it does not warpfrom humidity. Additionally, the finished product manufactured fromplastic does not require painting and is a solid color throughout soscratches from ordinary use are not readily visible. Finally, plastic iseasier to clean, can be produced with a glossy finish, and is generallymore durable than wood.

[0015]FIG. 1 and FIG. 2 show the preferred embodiment of the inventionwherein extruded rigid plastic bi-fold and half doors have two sidestiles and a top and bottom rail forming a generally rectangularconfiguration and have horizontal vanes covering the interior of thedoor. The stiles have mating cutouts formed along their interior edgefor receiving the vanes and holding the vanes in a permanently fixedposition relative to the stiles and rails when the stiles and rails areassembled into a rectangular configuration.

[0016] The preferred plastic material is PVC because of its strength,durability, and ease of extruding. However, other suitable materials,such as polyethylene and polypropylene could be used. The preferredformulation of PVC is about 65% to 75% PVC, about 12% to 18% calciumcarbonate, about 8% to 12% stabilizer, and about 3% to 7% titaniumdioxide. The especially preferred formulation is about 70% PVC, about15% calcium carbonate, about 10% stabilizer, and about 5% titaniumdioxide. The preferred ingredients include a tin stabilizer. Otheringredients include a paraffin wax lubricant, such as XL165, a processaid, such as methyl methacrylate which is commercially available asK-120N from Rohm & Haas, and an impact modifier, such as modifiedacrylic available as D-200 from Elf-Autochem. Titanium dioxide should beadded in an amount sufficient to impart the desired shade of white, andpigment may be added to achieve other color variations.

[0017] The basis extrusion process is old and well known to a personskilled in the art. Various dies may be used to extrude the individualpieces with a variety of profiles, but FIG. 3 shows the preferredcross-section view of a rail used for the top and bottom of thehorizontal rail section. Preferably, the door also has a middle rail ofthe same or similar configuration as the top and bottom rails. Thismiddle rail provides extra stability for the door and also provides ameans for attaching an opening mechanism, such a knob.

[0018]FIG. 4 shows the preferred construction of the side stiles. Thisconstruction also allows for hardware, such as hinges, to be securelyattached. Of, course, other designs are acceptable so long as theyprovide the needed strength and rigidity.

[0019]FIG. 5 shows the preferred construction of the slatted vanes thatcover the interior of the door. These vanes are basically hollow, butpreferably have one or more cross-members for support. The vanes aredesigned to fit into the side stiles in a permanently fixed positionwhen the door is fully assembled. The slatted vanes allow light and airto pass through the door yet provide a high degree of privacy. Becausethe vanes are somewhat flexible, an individual vane may be removed fromthe door and replaced with a new vane, if the need arises, withoutdisassembling the door.

[0020] The stiles and rails may be fastened together by any suitablemeans, such as glue or screws. The preferred method of construction is ascrew fastener. For aesthetic purposes, the screws should be countersunkso that the heads can be covered with a plug to make the assemblyvirtually invisible.

[0021] The hinges associated with mounting the bi-fold or two piece doorcould be standard metal hinges that attach to the stiles with screws. Inorder to securely fasten hardware to the doors, it is preferred thatsmall plastic anchors be inserted into the stiles where the screws forthe hinges and knob attach. These anchors will provide more support forthe screws than the relatively thin wall of the stiles and will helpprevent the screws from stripping during the final assembly.

[0022] This invention is directed mainly toward bi-fold and half doors,rather than full doors, because the vanes in a bi-fold and half door arerelatively short and will maintain their structural integrity ifpressure is applied on the vanes when the door is in use. However, thisinvention could be made to work well on a full size door by using acenter stile that would permit the use of short vanes on both sides ofthe center stile. Without a center stile on a full size door, the rigidplastic vanes covering an expanse of about two feet would tend to be tooflexible and would probably not be suitable. Alternatively, ifadditional supporting cross-members were added to the interior of thevanes or if the vanes were made thicker, they could be made to work on alarger expanse. The obvious disadvantage of this configuration would bethe expense of the extra material needed to make the vanes and theadditional weight of the door.

[0023] As is apparent from the foregoing description, there are variousmodes of carrying out the invention. It is to be fully understood thatall of the foregoing is intended to be merely illustrative and is not tobe construed or interpreted as being restrictive or otherwise limitingof the present invention.

I claim:
 1. A synthetic resinous plastic door having a generallyrectangular configuration comprising two vertical side stiles, and a topand bottom horizontal rail defining the perimeter of the door, and vanescovering the interior of the rectangular configuration, the stileshaving indentations along their interior edge for receiving the vanes soas to hold the vanes in a permanently fixed position relative to thestiles and rails when the stiles and rails are assembled into arectangular configuration, and the stiles, rails and vanes being formedby an extrusion process and having a substantially hollow interior withreinforcing cross-members, wherein the two panels of the door areattached to each other by a first hinge to permit folding of the doorand one of the panels is attached to a door frame by a second hinge. 2.The door of claim 1 further comprising a middle horizontal rail.
 3. Thedoor of claim 1 wherein the foamed plastic comprises about 65% to 75%PVC, about 12% to 18% calcium carbonate, about 8% to 12% stabilizer, andabout 3% to 7% titanium dioxide.
 4. The door of claim 3 wherein thefoamed plastic comprises about 70% PVC, about 15% calcium carbonate,about 10% stabilizer, and about 5% titanium dioxide.
 5. A syntheticresinous plastic door comprising two panels, each having a generallyrectangular configuration comprising two vertical side stiles, and atopand bottom horizontal rail defining the perimeter of the door, and vanescovering the interior of the rectangular configuration, the stileshaving mating indentations along their interior edge for receiving thevanes so as to hold the vanes in a permanently fixed position relativeto the stiles and rails when the stiles and rails are assembled into arectangular configuration, and the stiles, rails and vanes being formedby an extrusion process and having a substantially hollow interior withreinforcing cross-members, wherein the two panels of the door are eachattached a door frame by a hinge to permit the panels to open from themiddle.
 6. The door of claim 5 further comprising a middle horizontalrail.
 7. The door of claim 5 wherein the foamed plastic comprises about65% to 75% PVC, about 12% to 18% calcium carbonate, about 8% to 12%stabilizer, and about 3% to 7% titanium dioxide.
 8. The door of claim 7wherein the foamed plastic comprises about 70% PVC, about 15% calciumcarbonate, about 10% stabilizer, and about 5% titanium dioxide.
 9. Asynthetic resinous plastic door having a generally rectangularconfiguration comprising two vertical side stiles, and a top and bottomhorizontal rail defining the perimeter of the door, a vertical centerstile and vanes covering the interior of the rectangular configuration,the stiles having mating indentations along their interior edge forreceiving the vanes so as to hold the vanes in a permanently fixedposition relative to the stiles and rails when the stiles and rails areassembled into a rectangular configuration, and the stiles, rails andvanes being formed by an extrusion process and having a substantiallyhollow interior with reinforcing cross-members.
 10. The door of claim 9further comprising a middle horizontal rail.
 11. The door of claim 9wherein the foamed plastic comprises about 65% to 75% PVC, about 12% to18% calcium carbonate, about 8% to 12% stabilizer, and about 3% to 7%titanium dioxide.
 12. The door of claim 9 wherein the foamed plasticcomprises about 70% PVC, about 15% calcium carbonate, about 10%stabilizer, and about 5% titanium dioxide.